The objective of the proposed research is to augment the effectiveness of Chemotherapeutic agents against lymphoma cell populations by increasing the proportion of cells in active division. A number of -SH and -S-S-containing compounds have been found to possess mitosis promoting activity on certain mouse lymphomas in vitro. It is proposed to examine an extended list of such compounds in vitro and to determine whether these will be similarly effective in vivo. It is intended particularly to identify substances with specific activity on lymphoma cells. Since most cancer chemotherapeutic agents are active only against cells in the division cycle, the effect of concurrent treatment with mitosis promoting substances on the effectiveness of known chemotherapeutic agents will be examined. It is also proposed to examine the mechanisms whereby mitosis promoting substances act, and particularly to examine lymphoma cells for abnormalities in sulfur metabolism. Finally, it is proposed to prepare and examine enzymes of 3 further kinds, glutaminase-asparaginase, L-arginine desiminase and L-serine dehydrase, for tumor inhibitory activity particularly in combination with mitosis promoting substances.